Separation of minerals by flotation



Patented Dec. 10,1929

UNITED STATES PATENT OFFICE FREDERICK MOSES, OF NEW YORK, AND RAYMOND W. HESS, OF BUFFALO, AND BOB- ERT L. PERKINS, OF EAST AURORA, NEW YORK, ASSIGNORS TO THE BARRETT COI- PANY, OENEW YORK, N". Y., A CORPORATION OF NEW JERSEY SEPARATION OF MINERALS BY FLOTATION 1 In carrying out the flotation process, the flotation agent comprising a pyridyl mercaptan, which may be prepared by methods described in the literature of organic chemistry, may be incorporated with the ore or mineral ulp in any suitable manner or at any suita le time which will insurea satisfactory flotation operation. For example, it

may be introduced, in the free state or ass. to salt, into the mill in which the ore is being ground, or it may be dissolved, suspended, or dispersed in any suitable solvent or dispersing agent as, for example, in one or more of the usual flotation oils'or oilmixtures, or in any suitable organic solvent or medium, or 'in water or in alkali oran alkaline reagent, and the resulting solution, suspension, or dispersion incorporated with the ore or mineral pulp. While the agents of the present invention show marked action as flotation or collecting agents in ore concentration, they ordinarily insuflicientfrothing qualand are therefore, generally used to advantage in conjunction with any suitable or well-known frothing agent, e. g. pine 'oil, crude turpentine, coal tar acids, etc. They may sometimes used-to advantage in conjunction =with other flotation agents. They bef'employed in the pure or puri:

was

1827. Serial No. 193,088.

fied state and, in general, they may also be 'employed'in the crude or impure state.

The process of the present invention can be carried out in any suitable apparatus, for example, those of the pneumatic type such as the'Callow cell, or those where the air is incorporated with the mixture by agitation such as the-Janney apparatus, or the like.

It is of advantage-in some cases, as with certain copper ores, to subject the ore pulp to the action of an amount of alkali, sufli'- cient to give it an alkaline reaction before subjecting it to flotation with the flotation agents of the present invention. The alkali may be caustic alkali such as caustic soda, or an alkaline salt such as soda ash, or it may be calcium oxide or hydrate.

In the difierentialseparation, of various minerals, such as zinc blende from associated minerals, the presence of an alkali metal cyanide, or of copper sulfate or other salts, is sometimes advantageous.

The amount of flotation agent required to be used in .the flotation process will vary, it

depending partly on the character and composition of the ore, partly on the particular pyridyl mercaptan compound employed, and partly on other factors. Ordinarily, onesixth to one-half pound of the flotation agent per ton of dry ore will be suflicient, but larger or smaller amounts than this may be used.

The invention will be further illustrated by the-following specific example, but it will be understood that the invention is not limited thereto. The parts are by weight.

Example: 500 parts of a copper sulfide ore (of the Inspiration Copper Company) assaymg 1.37 percent copper, was ground in a ball mill with 250 parts of water, 0.75 parts of hydrated lime (equivalent' to 3 pounds per ton of ore) and 0.0625 parts of pyridine-2- thiol (equivalent to one-fourth pound per ton of'ore) until practicallyall ofit was suflicientlv fine to pass through a LO-mesh screen, ground pulp was diluted with su'flicient water to give a pulp containing about 16 reent solids and subjected to flotation ina anney mechanical ap aratus. The agitated for 30 minutes during which time about 0.12 parts of pine oilwae introduced. 41.5 parts of a concentrate assaying 11.22 percent copper was obtained which is a recovery in the concentrate of 67.7 percent of the copper. The tailings assayed 0.48 percent copper. It will be noted that the equivalent of about 12.1 tons of ore was required to give one ton of concentrate.

It will thus be noted that the present inrention contemplates the utilization as flota- .ion agents in the separation of minerals and the concentration of ores of pyridyl mercaptans; that the said flotation agents may be incorporated with the ore or mineral pulp at any suitable time and in any suitable manner; that they may be used in the free state or as salts or in admixture with one another or in solution, suspension or dispersion in any suitable solvent or medium; and that they may be used in conjunction with other flotation agents or with frothing agents,,or

with both. 7

The present invention is of more or less general application to the flotation treatment of different kinds of mineral substances, both natural and artificial, by flotation.

. It will be further understood that the invention is not limited to the use of the particular agents or ingredients mentioned in the example and that other agents, particularly other flotation agents of the class specified, can be similarly used.

We claim: 1. In efl'ecting the separation of minerals, the process which comprises incorporating a pyridyl mercaptan with the mineral pulp, and subjecting the resulting mixture to a flotation operation.

2. In efl'ecting the separation of minerals, the process which comprises incorporating 40 pyridine-2-thiol with the mineral pulp and subjecting the resulting mixture to a froth v flotation operation.

3. In effecting the concentration of a copper sulfide ore, the process which comprises 4 incorporating a pyridyl mercaptan with a copper sulfide ore, pulp, and subjecting the resulting mixture to a flotation operation.

4. In effecting the concentration of a copper sulfide ore, the process which comprises incorporating pyridine-2-thiol with a copper sulfide ore pulp, and subjecting the resulting mixture to a froth flotation operation.

In testimony whereof we aflix our signatures. FREDERICK G. MOSES.

RAYMOND W. HESS. ROBERT L. PERKINS. 

